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United States Patent |
6,001,396
|
Bayer
,   et al.
|
December 14, 1999
|
Method and solution for improving frozen seafood quality
Abstract
A method for improving the quality of frozen seafood by enhancing flavor
and shelf-life so that the seafood can be stored under commercial
conditions. This method includes injection of substances into the flesh or
circulatory system of live fish and whole seafood prior to cooking or
freezing. These injected substances include antioxidants and
cryoprotectants which circulate throughout the tissues, allowing for a
uniform distribution throughout the flesh of the animal. The animal is
then frozen, or cooked and then frozen, and stored for later use. The
present invention is also directed to a solution for injecting into live
fish and whole seafood in accordance with the method of the present
invention.
Inventors:
|
Bayer; Robert C. (Orono, ME);
Bushway; Alfred A. (Veazie, ME);
Work; Therese M. (Bangor, ME)
|
Assignee:
|
University of Maine (Orono, ME)
|
Appl. No.:
|
110739 |
Filed:
|
July 2, 1998 |
Current U.S. Class: |
426/2; 426/281; 426/643; 426/652 |
Intern'l Class: |
A23L 001/33 |
Field of Search: |
426/2,281,643,652
|
References Cited
U.S. Patent Documents
2563364 | Aug., 1951 | Proctor | 426/2.
|
3692545 | Sep., 1972 | Moore | 426/2.
|
4336274 | Jun., 1982 | Ross et al. | 426/643.
|
4572838 | Feb., 1986 | Lanier et al. | 426/643.
|
5436025 | Jul., 1995 | Rogols et al. | 426/643.
|
Primary Examiner: Corbin; Arthur L.
Attorney, Agent or Firm: Persson; Michael J., Ritchie; William B.
Parent Case Text
This application claims benefit of provisional application No. 60/052,736
filed Jul. 8, 1997.
Claims
What is claimed is:
1. A method of improving quality of frozen sea animals comprising the steps
of:
obtaining a live sea animal;
injecting said live sea animal with a solution comprising at least one
antioxidant and at least one cryoprotectant; and
freezing said sea animal.
2. The method as claimed in claim 1 wherein said solution of said injecting
step further comprises at least one spice.
3. The method as claimed in claim 2 wherein said solution comprises at
least one antioxidant selected from the group consisting of a tocopherol,
an ethoxyquin, BHT, BHA, TBHG, a carotenoid, and a retinoid.
4. The method as claimed in claim 2 wherein said solution comprises at
least one cryoprotectant selected from the group consisting of sucrose,
sorbitol, xylitol, high fructose corn syrup, and corn syrup.
5. The method as claimed in claim 2 wherein said solution comprises at
least one spice selected from the group consisting of garlic, leeks,
cayenne, butter forms, soy sauce, onions, shallots, jalapenos, ginger,
teriyaki sauce, mace, and rosemary.
6. The method as claimed in claim 1 wherein said live sea animal is a
lobster.
7. The method as claimed in claim 6 further comprising the step of killing
said lobster before performing said freezing step.
8. The method as claimed in claim 6 wherein said step of injecting said
live sea animal comprises the step of injecting said lobster such that
said solution substantially uniformly perfuses into tissues of said
lobster.
9. The method as claimed in claim 8 wherein said step of injecting said
live sea animal comprises the step of injecting said lobster at a point
selected from the group consisting of a ventral sinus, a dorsal sinus, a
heart, a membrane of the tail, and a joint.
10. The method as claimed in claim 1 wherein said solution comprises at
least one antioxidant selected from the group consisting of a tocopherol,
an ethoxyquin, BHT, BHA, TBHG, a carotenoid, and a retinoid.
11. The method as claimed in claim 1 wherein said solution comprises at
least one cryoprotectant selected from the group consisting of sucrose,
sorbitol, xylitol, high fructose corn syrup, and corn syrup.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to flavor and shelf life enhancement of fish
and whole seafood prior to cooking or freezing and to the maintenance and
enhancement of the cooked yield of fish and whole seafood. In particular,
the present invention relates to methods for maintaining or enhancing the
flavor, shelf life and cooked yield of Maine lobsters.
2. Description of the Related Art
The quality and taste of seafood is known to deteriorate as oxidation
occurs and ice crystals disrupt the cells and tissue. The freezing
preservation of whole seafood so that the food tastes substantially like
fresh has been so difficult, for example, when compared to the problems
associated with freezing meat, that the U.S. Government financed research
in this field for many years. Despite this effort, little success has been
obtained and the program has now been terminated.
Representative of this type of effort is found in U.S. Pat. No. 4,336,274,
issued to Ross et al. on Jun. 22, 1982, which discloses a whole blue crab
freezing process. This process includes the use of sugar in the boiling
and cooling baths and the retention of this sugar water within the shell
of the whole blue crab during freezing and storage. However, only sugar is
disclosed as a flavor and shelf life enhancer, and only immersion is
disclosed as a method of application. Further, the process is disclosed
for whole blue crabs only.
Various attempts have been made in the beef industry to improve the quality
of meat. Swift and Codeveloped one of the most promising. In this process,
an injection of a clarified, concentrated, standardized proteolytic enzyme
(papain) is injected into the animal's jugular vein minutes before
slaughter. The size of the injection is dependent upon the weight and
grade of the animal. The tenderizing enzyme is carried to all parts of the
body through the blood stream and results in a significant increase in
tenderness. The purpose of this process was limited to making the meat
tenderer and was limited to beef.
A method of improving the quality of frozen seafood, particularly lobsters,
which can be used with additives other than sugar and places the additives
uniformly into the flesh of the animal prior to cooking or freezing is not
disclosed in the prior art.
SUMMARY OF THE INVENTION
The present invention is an injection method for introducing components
into the flesh of fish and whole seafood, prior to cooking or freezing, to
maintain or enhance flavor, shelf life, and cooked yield. The principle
injectants include cryoprotectants, antioxidants and flavor enhancers. In
the preferred method of the present invention, these materials are
disposed with a liquid to form a solution that is manually or mechanically
injected into a live lobster at predetermined points along the body of the
lobster such that the solution uniformly perfuses through the tissues of
the lobster. It is preferred that between 0.1 and 10 cubic centimeters
(c.c.) of solution be injected and that the injected solution have
concentrations of between 0.5% and 3% of a cryoprotectant, such as sugar
or sugar alcohol, and between 100 and 1000 parts per million (ppm) of an
antioxidant, such as a mixed function water dispersible tocopherol.
Therefore, it is an aspect of the invention to provide a method to improve
the quality of frozen seafood to prevent any substantial loss of fresh
flavor and texture.
It is still another aspect of the invention to provide a method to improve
the quality of frozen seafood that yields frozen fish and whole seafood
which are as commercially acceptable to the public as the fresh products.
It is still another aspect of the invention to provide a method to improve
the quality of frozen seafood that can assure a steady supply of these
products regardless of the season.
It is still another aspect of the invention to provide a method to improve
the quality of frozen seafood that minimizes the risk of food poisoning.
It is still another aspect of the invention to provide a method of fish and
whole seafood preservation, which reduces spoilage in order to conserve
these natural resources.
These aspects of the invention are not meant to be exclusive and other
features, aspects, and advantages of the present invention will be readily
apparent to those of ordinary skill in the art when read in conjunction
with the following description, appended claims and accompanying drawings.
DETAILED DESCRIPTION OF THE INVENTION
The invention is an injection method used to inject the food animal while
it is still alive. A food additive injection apparatus, as commonly used
in the meat processing industry, may be used. This apparatus may consist
of a gas, fluid, or manually driven pump which forces additives in
solution from a reservoir through a length of tubing and a hollow needle
into the flesh to be injected. An alternative method may use a syringe
instead of a pump and tubing. Other, alternative methods of injecting
liquids into muscle tissue are acceptable. Fresh seafood, preferably
lobsters, are injected at various points with antioxidants,
cryoprotectants, flavors, or other substances. If fish are selected,
injection directly into the flesh at regular intervals is appropriate. In
whole seafood, such as lobsters, injection points may include ventral or
dorsal sinuses, the heart, and membranes of the tail, the joints or any
point, which gives access to the circulatory system. Such injection causes
these substances to perfuse uniformly into the tissues. Uniform perfusion
has been demonstrated in whole lobsters by dye injection into these
locations, followed by observation of the appearance of the dye throughout
the crustacean's tissues.
When antioxidants are injected, lipid oxidation is reduced as measured by
TBA methodology, giving values in mg/kg malonaldehyde. Antioxidants that
may be injected include tocopherols, ethoxyquins, BHT, BHA, TBHG,
carotenoids and rentinoids. Cryoprotectants, when injected into fish or
whole seafood, enhance flavor as well as texture and shelf life.
Antioxidants interact with cryoprotectants to increase shelf life.
Cryoprotectants that may be used include sucrose, sorbitol, Xylitol, high
fructose corn syrup and corn syrup.
Spices, when injected into fish or whole seafood, also enhance flavor.
Additionally, some spices offer antioxidant properties. Spices that may be
used include garlic, leeks, cayenne, butter forms, soy sauce, onion,
shallots, jalapeno, ginger, teriyaki sauce, spices with antioxidant
properties, mace and rosemary.
EXAMPLE
While the examples that are presented use Maine lobsters, those skilled in
the art will recognize that any seafood such as blue crabs, rock lobsters,
fish, etc. can be utilized. Lobsters of mixed size taken commercially from
Maine waters in late October were prepared. Sample treatments included a
combination of sucrose and antioxidant at the following levels:
a) 1 g sucrose+2.5 g antioxidant/lobster
b) 2 g sucrose+2.5 g antioxidant/lobster
c) 3 g sucrose+2.5 g antioxidant/lobster
d) Untreated-Control
After injection, these lobsters were immobilized by chilling, stacked in
layers 2 or 3 lobsters high, and boiled by immersion for 10 minutes. The
lobsters were then frozen by immersion in a bath of "Freon 12" liquid gas
until boiling stopped. The lobsters were then removed from the Freon bath,
hermetically sealed in plastic, and stored in a commercial type of
freezer. The samples will be held for up to 15 months under commercial
storage practices. Initially and at three-month intervals, the samples are
evaluated by a sensory panel and analyzed for chemical and physical
characteristics. Moisture and fat content will be analyzed according to
AOAC (1190) methods 950.46B and 960.39A, respectively. Salt soluble
protein analysis is obtained by using 10 g samples of tissue homogenized
with 90 ml of 5% NaCI for 30 seconds. The homogenate is spun for 20
minutes at 20,000 rpm (48,000.times. g) on a Sorval RC-2-B centrifuge. The
supernatant is collected as the salt soluble fraction. The protein content
in the soluble fraction is determined by the method of Lowry (91951).
Warner Bratzler texture is measured for crusher claws and tail samples
(Larmond and Petrasovits, 1972).
Sensory Evaluation--First Results
The samples for initial testing were placed in frozen storage for 12 hours
at 4.degree. C. until thawed. Five lobsters of each treatment were
prepared. Due to time constraints, the samples were not fully thawed when
steamed. Therefore, instead of steaming for 2-3 minutes as is commonly
practiced, the samples were steamed for 5 minutes prior to testing.
Lobster tails were removed from the shell and cut into 6 pieces, resulting
in 30 commingled pieces from each treatment. A trained descriptive sensory
panel of nine members was used to evaluate the sweetness, overall and
textural attributes of the lobsters using techniques well known in the
art. Data was analyzed by multi variant statistical methods using SAS
(1991) software.
The results of the initial sensory evaluation tests are shown in Table 1,
below.
The sweetness of the control and 1 g sucrose treatment were significantly
lower than the 2 and 3 g treatments of sucrose indicating the panelists
could detect the difference between the control and 2 g or 3 g samples.
When asked to indicate their overall acceptability rating of the samples
statistically, no significance difference is reported. The mean scored for
overall correspond to "like slightly" for the control and 2 g sucrose and
"like moderately" for 1 g and 3 g. The flavor of the 1 g treatment was
scored as "bland" when compared to "slightly lobster" for the 2 g and 3 g
samples and "moderately lobster" for the control. The texture of the
samples can be summarized as "slightly" tender, fibrous and moist.
TABLE 1
______________________________________
Sensory mean scores of control and cryoprotectant lobster treatments
Initial Testing
Quality
Control 1 g. sucrose
2 g. sucrose
3 g. sucrose
______________________________________
Sweetness
2.3 b 2.1 b 3.0 a 3.3 a
Overall
5.9 a 6.6 a 5.8 a 6.7 a
Flavor 6.0 a 4.0 b 5.0 ab 4.9 ab
Tender/
3.1 b 4.3 ab 5.0 a 4.8 bc
Tough
Mush/ 4.7 a 5.0 a 4.9 a 4.2 a
Fibrous
Dry/Moist
5.7 a 4.8 bc 4.4 c 5.4 ab
______________________________________
Note: Means followed by similar letters are not significantly different.
Lipid oxidation of rancidity was measured using TBA methodology. The TBA
values are reported in Table 2 below. The lower the TBA values the lower
the level of oxidation that has occurred in the samples. The analysis
indicates a significant correlation between higher sucrose levels and
increased antioxidant effect.
TABLE 2
______________________________________
TBA values (mg/kg malonaldehyde) of control and
cryoprotectant lobster treatments
Initial Testing
Treatment TBA
______________________________________
Control .92 a
1g sucrose .78 b
2g sucrose .67 c
3g sucrose .47 d
______________________________________
While there have been described what are at present considered to be the
preferred embodiments of this invention, it will be obvious to those
skilled in the art that various changes and modifications may be made
therein without departing from the invention and it is, therefore, aimed
to cover all such changes and modifications as fall within the true spirit
and scope of the invention.
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